Digital smart real showcase control system, method, and program

ABSTRACT

A digital smart real showcase control system ( 100 ) can control a showcase with minimum required energy by quickly and properly controlling the showcase as a result of comprising an external air temperature input unit ( 11 ) configured to input an external air temperature, an external air temperature table ( 12 ) that stores past external air temperatures, an external air temperature prediction unit ( 13 ) configured to predict a future predicted external air temperature, an indoor temperature input unit ( 14 ) configured to input an indoor temperature, an indoor humidity input unit ( 15 ) configured to input an indoor humidity, an indoor enthalpy storage unit ( 16 ) configured to store past indoor enthalpies, an indoor enthalpy prediction unit ( 17 ) configured to predict a future predicted indoor enthalpy, a showcase control unit ( 18 ) configured to control a showcase temperature based on a predicted external air temperature and a predicted indoor enthalpy.

TECHNICAL FIELD

The present invention relates to a digital smart real showcase control system, method, and program to control a showcase for displaying frozen products and refrigerated products in a supermarket, a convenience store, etc.

BACKGROUND ART

In a store such as a supermarket or convenience store, showcases to display drinks and foods, etc., while refrigerating or freezing them are used. A freezing and refrigerating showcase to be installed in a store such as a supermarket is equipped with a freezing device, which blows cold air into the chamber of the showcase displaying products from an air outlet to cool the inside of the chamber to a predetermined temperature, and sucks the blown cold air from a suction opening and cools and discharges it again as cold air into the chamber.

A cooling temperature inside the chamber differs depending on the kind of product stored in the chamber, and an in-chamber temperature is set for each showcase. This setting of a target temperature inside the chamber is performed by a freezing and refrigerating showcase controller installed for each showcase. Once a target temperature is set, an in-chamber temperature is detected, and a solenoid valve of the freezing device is controlled to open or close for a temperature control so that the in-chamber temperature becomes close to the target temperature.

PTL 1 describes a showcase control system comprising an external air temperature input means configured to input external air temperature information, an external air temperature coefficient calculation means configured to calculate, based on an external air temperature calculated from the external air temperature information input by the external air temperature input means, a ratio of a current external air temperature to an external air temperature at a maximum temperature in air-cooling, and a ratio of a temperature difference between a current external air temperature and a predetermined room temperature to a temperature difference between an external air temperature at a minimum temperature and the room temperature in air-heating, as an external air temperature coefficient, a peak operating rate calculation means configured to calculate an average operating rate of an air conditioner at the maximum temperature in air-cooling, and an average operating rate of the air conditioner at the minimum temperature in air-heating, as a peak operating rate, an average operating rate calculation means configured to calculate an hourly average operating rate by multiplying the peak operating rate calculated by the peak operating rate calculation means by the external air temperature coefficient calculated by the external air temperature coefficient calculation means, an average surplus rate calculation means configured to calculate (1−average operating rate) as an average surplus rate with respect to the average operating rate calculated by the average operating rate calculation means, a control rate calculation means configured to calculate a control rate whose maximum value is a predetermined value for the average surplus rate calculated by the average surplus rate calculation means, an air-conditioning control means configured to perform energy-saving control of the air conditioner by a quantity of the control rate calculated by the control rate calculation means, a case control rate calculation means configured to calculate a case control rate for performing energy-saving control of the showcase, and a case control means configured to perform energy-saving control of the showcase by a quantity of the control rate calculated by the case control rate calculation means.

CITATION LIST Patent Literature [PTL 1] JP 4822303 B SUMMARY OF INVENTION Technical Problem

However, in such a conventional showcase control system, a feedback control is performed in which an external air temperature is detected and a showcase is controlled based on the detected external air temperature, so that the showcase control is a follow-up control, and the system cannot perform a quick and proper control.

An object of the present invention is to provide a digital smart real showcase control system, method, and program capable of controlling a showcase with minimum required energy by quickly and properly controlling the showcase.

Solution to Problem

A digital smart real showcase control system according to the present invention comprises an external air temperature input means configured to input external air temperature information, an external air temperature prediction means configured to predict a future predicted external air temperature from external air temperature information inputted by the external air temperature input means, and a control means configured to control a showcase temperature based on a predicted external air temperature predicted by the external air temperature prediction means.

With this configuration, the showcase is controlled not by following an external air temperature but based on an external air temperature predicted in advance, so that the showcase is quickly and properly controlled, and accordingly, the showcase can be controlled with minimum required energy.

In addition, the digital smart real showcase control system comprises a storage means configured to store past external air temperatures, and by predicting a predicted external air temperature based on data stored in the storage means, the external air temperature prediction means can predict the future from a current external air temperature by referring to how the temperature changed with respect to a current time in the past by using past data.

The control means can perform a fine energy-saving control according to a deviation of the showcase temperature from a target temperature by controlling operation of the showcase according to a temperature-dependent control coefficient being a control coefficient according to the deviation.

By predicting a predicted external air temperature for a time corresponding to a length of a refrigerant pipe connecting the showcase and a freezing machine, ahead, the external air temperature prediction means can control the showcase based on the predicted external air temperature for the time corresponding to the length of the refrigerant pipe, ahead (future), so that the showcase is quickly and properly controlled, and accordingly, the showcase can be controlled with minimum required energy.

In addition, the digital smart real showcase control system comprises an indoor temperature input means configured to input indoor temperature information, an indoor humidity input means configured to input indoor humidity information, and an indoor enthalpy prediction means configured to predict a predicted indoor enthalpy being a future total wet air heating value of indoor air from an indoor temperature inputted from the indoor temperature input means and an indoor humidity inputted from the indoor humidity input means, and the control means controls a showcase temperature based on an indoor enthalpy predicted by the indoor enthalpy prediction means, and accordingly, an indoor enthalpy is predicted, and based on the predicted external air temperature and indoor enthalpy, the showcase is controlled, so that by reflecting an estimation result of a predicted heat load in showcase control, a highly effective showcase energy-saving control is realized.

The control means controls the showcase to the predicted external air temperature based on a predicted bias external air temperature obtained by adding a bias temperature for correcting a high temperature around the condenser, and accordingly by using, in place of the predicted external air temperature, a predicted bias external air temperature around the condenser higher in temperature than an external air temperature, the control means can perform a more proper showcase control in consideration of a high external air temperature around the condenser as well.

In addition, a digital smart real showcase control method according to the present invention comprises an external air temperature input step of inputting external air temperature information, an external air temperature prediction step of predicting a future predicted external air temperature from external air temperature information inputted by the external air temperature input step, and a control step of controlling a showcase temperature based on a predicted external air temperature predicted by the external air temperature prediction step.

Further, the present invention provides a program to make a computer function as a digital smart real showcase control system comprising an external air temperature input means configured to input external air temperature information, an external air temperature prediction means configured to predict a future predicted external air temperature from external air temperature information inputted by the external air temperature input means, and a control means configured to control a showcase temperature based on a predicted external air temperature predicted by the external air temperature prediction means.

Advantageous Effects of Invention

According to the present invention, by predicting a future external air temperature and controlling a showcase, a digital smart real showcase control system, method, and program capable of controlling a showcase with minimum required energy by quickly and properly controlling the showcase can be realized.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a configuration of a digital smart real showcase control system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a showcase in the digital smart real showcase control system according to the embodiment of the present invention.

FIG. 3 is a flowchart showing an energy-saving control operation of the digital smart real showcase control system according to the embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment to carry out the present invention is described in detail with reference to the accompanying drawings.

Embodiment

FIG. 1 is a block diagram showing a configuration of a digital smart real showcase control system according to an embodiment of the present invention. The present embodiment is an example of application to an air conditioning control system, and an air conditioning control is not essential for the present invention.

[Overall Configuration]

As shown in FIG. 1, a digital smart real showcase control system 100 comprises an external air temperature input unit 11 (external air temperature input means), an external air temperature table 12 (storage means), an external air temperature prediction unit 13 (external air temperature prediction means), an indoor temperature input unit 14, an indoor humidity input unit 15, an indoor enthalpy table 16 (storage means), an indoor enthalpy prediction unit 17 (enthalpy prediction means), a showcase control unit 18 (control means), and an air conditioning control unit 19 (control means).

An external air thermometer 20, an indoor thermometer 30, an indoor hygrometer 40, a showcase 50, and an air conditioner 60 are described for purpose of illustration of the digital smart real showcase control system 100.

The indoor thermometer 30 is a temperature sensor to detect a temperature of indoor air. The indoor hygrometer 40 is a humidity sensor to detect a humidity of indoor air.

<External Air Temperature Prediction Unit 13>

The external air temperature input unit 11 inputs a current external air temperature from the external air thermometer 20.

The external air temperature table 12 stores past external air temperatures for prediction of an external air temperature.

Here, the “external air temperature” in this description means an air temperature of the outside of a building, and is equal to an air temperature that a meteorological agency issues in principle, however, it is assumed to fluctuate or vary locally.

The external air temperature prediction unit 13 predicts an external air temperature and passes the predicted air temperature to the showcase control unit 18 and the air conditioning control unit 19.

For the external air temperature prediction, there are methods; a <<past data-using prediction method>> in which an external air temperature is predicted by using past data, and an <<external data-using prediction method>> in which an external air temperature is predicted by using data of an external agency.

<<Past Data-Using Prediction Method>>

The external air temperature prediction unit 13 predicts how the temperature will change (whether the temperature will increase or decrease, and the degree of the increase or decrease) in the future (for example, in how many minutes). In the external air temperature table 12, external air temperature data at, for example, half-hour intervals over the past one year for checking temperature changes to find how the temperature changed with respect to a current time in the past is stored. Based on past data read out from the external air temperature table 12, the external air temperature prediction unit 13 predicts the future from a current external air temperature by referring to how the temperature changed with respect to a current time in the past. This is specifically described below.

The external air temperature prediction unit 13 stores external air temperatures at, for example, half-hour intervals in the past one year in the external air temperature table 12 in advance, and predicts an external air temperature by reading out the stored external air temperature as an external air temperature predicted value.

Generally, in a case where air temperatures in each time period are just aggregated and used, variations among days and times are large, and when obtaining a future predicted value from meteorological data with the large variations, accuracy becomes insufficient. Therefore, instead of using record values of air temperatures in each time period as they are, the external air temperature prediction unit 13 predicts an external air temperature by the following methods (1) to (4) and stores the predicted external air temperature in the external air temperature table 12.

(1) Air temperature record values (for example, at intervals of 30 minutes) in a target region are acquired. (2) Meteorological data of the target region is acquired. (3) A reference curve showing a temperature change in each time period (for example, a curve showing changes from a minimum temperature to a maximum temperature, for each region) is created. Specifically, for each region, external air temperatures in respective time periods from 0:00 to 24:00 on each day in a year and temperature changes as reference curves in each of the time periods are stored. Even though the external air temperature on a target day differs year by year, by statistically accumulating the external air temperatures as past data, a temperature change in each time period on the target day can be represented by a reference curve showing a temperature change in a target time period. In the external air temperature table 12, air temperature record values and reference curves in a target region are stored (accumulated).

(4) An external air temperature predicted value in each time period is calculated from an acquired external air temperature and temperature change in each time period on the target day represented by the reference curve. That is, the acquired external air temperature is predicted to change with a temperature change gradient shown by the reference curve in a next time period (for example, in one hour; except for after 5 minutes, 15 minutes, 30 minutes, etc., which are calculated by linear interpolation). For example, it is assumed that an external air temperature table 12 as shown in Table 1 described later has been obtained. A change amount between the external air temperature of “31.0° C.” at 10 a.m. and the external air temperature of “31.5° C.” at 11 a.m. in Table 1 (in detail, a gradient of a temperature change shown by the reference curve) is assumed to be substantially constant in each time period on each day in each season, and to obtain a value for, for example, one hour later, a value obtained by adding this temperature change amount of “0.5” to an acquired external air temperature is regarded as a predicted value one hour ahead. For 15 minutes later, a value obtained by adding “0.5/4” is regarded as a predicted value 15 minutes ahead.

The external air temperature prediction unit 13 predicts a future (for, for example, one hour ahead) external air temperature by using a current external air temperature and the past data (here, past record values and the reference curve in each time period) stored in the external air temperature table 12. In the case described above, to obtain an external air temperature after 30 minutes, by adding (subtracting) ½ of a temperature change shown by the reference curve to (from) the current external air temperature, an external air temperature predicted value after 30 minutes is obtained. When obtaining a value after 15 minutes or after 2 hours or more, an external air temperature predicted value can be obtained by the same method.

In this way, the external air temperature prediction unit 13 creates a reference curve representing changes in air temperature per a day based on past air temperature record values, and predicts an air temperature based on the reference curve. The external air temperature prediction unit 13 does not regard an average value or a central value of past air temperature record values as a current air temperature, but predicts an air temperature according to a tendency of a change in air temperature per a day based on the change in temperature stored in the external air temperature table 12, so that prediction accuracy can be improved.

<<External Data-Using Prediction Method>>

As described in the <<past data-using prediction method>> described above, the use of past data for prediction is a mere example, and the method is not limited to this. For example, the external air temperature prediction unit 13 can also adopt the following <<external data-using prediction method>>.

The external air temperature prediction unit 13 predicts an external air temperature by using, for example, a temperature forecast for a target day issued by a meteorological agency. The external air temperature prediction unit 13 predicts a future external air temperature by referring to a change in the temperature forecast (temporal differentiation, that is, a tendency of a temperature change) issued by a meteorological agency, with respect to a current external air temperature. For example, the external air temperature prediction unit 13 can receive data (meteorological data) including forecasted values issued by a meteorological agency or a meteorological company by accessing a computer of a meteorological agency or a meteorological company.

<Indoor Enthalpy Prediction Unit 17>

The indoor enthalpy table 16 stores past indoor enthalpies for prediction of an indoor enthalpy (refer to Table 1).

The indoor enthalpy prediction unit 17 predicts an indoor enthalpy by referring to the indoor enthalpy table 16. Specifically, the indoor enthalpy prediction unit 17 predicts an enthalpy (referred to as a specific enthalpy as well) being a total wet air heating value of indoor air based on an inputted indoor air temperature and humidity and a table value in the indoor enthalpy table 16. An enthalpy in the present embodiment represents an enthalpy that 1 kg of a substance (air) has, and a unit for the enthalpy is (kJ/kg D.A.).

<Showcase Control Unit 18>

The showcase control unit 18 controls a temperature for freezing or refrigerating articles in a showcase. Specifically, it is, for example, a freezing machine or a refrigeration machine, and is preferably subjected to energy-saving control. For example, control rates are calculated and programmed in advance based on average sales-space temperatures and specific enthalpy values (total air heating value) per month, per business hour, non-business hour, or per day and night, etc., and the operation for freezing or refrigerating is performed as energy-saving control by a quantity of the control rate.

In addition, the showcase control unit 18 predicts a future predicted external air temperature for a time corresponding to a length of the refrigerant pipe 130 (refer to FIG. 2), ahead from inputted external air temperature information, and controls the temperature of the showcase 50 based on the predicted external air temperature (described in detail below).

<Air Conditioning Control Unit 19>

In the present embodiment, an operating rate in the showcase control unit 18 (hereinafter, this operating rate is called “showcase operating rate”) which controls a temperature for freezing or refrigerating articles in a showcase is detected, and in the case where the showcase operating rate exceeds a predetermined value, the energy-saving control of the air conditioner 60 is curtailed or stopped, which lowers a temperature of a sales-space where the showcase is installed, to lower the showcase operating rate to the predetermined value or less, thereby achieving energy saving of the store as a whole. In addition, as an assumable case where a sales-space rises in temperature to an unintended temperature, for example, there may be a case where it is impossible to detect only with a temperature that a controlled showcase is in overload because this system is incapable of detecting that a specific enthalpy value (total air heating value) being high unless the humidity of the sales-space is measured, a case where it is impossible for the control of air-conditioning to follow an upsurge in visitors, or the like.

The air conditioning control unit 19 calculates a control rate for an energy-saving control of the air conditioner 60, and performs the energy-saving control of the air conditioner 60 according to the calculated control rate without excess and deficiency. In the control, the air conditioner 60 may be stopped (turned off) in a predetermined pattern, or may be inverter-controlled.

The external air temperature prediction unit 13, the indoor enthalpy prediction unit 17, the showcase control unit 18, and the air conditioning control unit 19 described above are constructed by an arithmetic control unit such as a personal computer. The arithmetic control unit consists of a CPU (Central Processing Unit) or the like, controls the entire system, and is made to function as a digital smart real showcase control system by executing an air conditioning energy-saving control program.

The external air temperature table 12 and the indoor enthalpy table 16 described above are stored in a storage unit (storage means) such as a nonvolatile memory or an external storage device, etc.

FIG. 2 is a configuration diagram of a showcase of the digital smart real showcase control system 100. The present embodiment is an example of application to a control system of a refrigerating and freezing showcase installed in a store.

As shown in FIG. 2, the digital smart real showcase control system 100 comprises a showcase 50, a freezing machine 120, a refrigerant pipe 130, and a showcase control unit 18.

The showcase control unit 18 controls the freezing machine 120, etc., for the showcase 50. The installation location of the showcase control unit 18 is not limited to this example. For example, the showcase control unit 18 may be installed in a machine room 110 b at a bottom portion of a showcase main body 50 a, or may be installed on a back surface of the showcase main body 50 a, or at a location away from the showcase main body 50 a.

The showcase 50 is installed in a store such as a supermarket or convenience store, and displays products to be cooled, such as drinks and foods, etc.

The showcase 50 comprises a showcase main body 50 a having a product storing space, and an air outlet 111 to blow out cold air downward is formed at an upper portion of the showcase main body 50 a, and a suction opening 112 to suction cold air that has descended along an air curtain is formed at a lower portion. At the bottom portion of the showcase main body 50 a, as the machine room 110 b, a solenoid valve 113 provided in the refrigerant pipe 130, an expansion valve 114 that changes a high-pressure liquid refrigerant into a low-pressure liquid, and a fan motor 115 that circulates the cold air are provided. The showcase 50 comprises, at the back surface side of the showcase main body 50 a, a cooler (evaporator) 116 that evaporates the low-pressure liquid refrigerant that has been changed into a low-pressure liquid by the expansion valve 114 while drawing heat from the low-pressure liquid refrigerant.

The showcase 50 comprises, in the product storing space of the showcase main body 50 a, shelf plates 117 and a bottom plate 118 being store shelves, and an air curtain 119 covering the product storing space. The inside of the showcase 50 is cooled to a temperature suitable for products to be displayed on the shelf plates 117 and the bottom plate 118 (hereinafter, called store shelves).

At the air outlet 111, a temperature sensor 131 that detects a temperature of the store shelves of the showcase 50 (hereinafter, called temperature of the showcase 50) is provided. The air outlet 111 is at a place where a temperature closer to a temperature set as a target is detected, and a sensor temperature detected by the temperature sensor 131 is regarded as a temperature of the showcase 50. An installation location of the temperature sensor 131 and the number of attached temperature sensors 131 are not limited to this example.

The freezing machine 120 is connected to the showcase main body 50 a via the refrigerant pipe 130. The freezing machine 120 comprises a compressor 121, a condenser 122, and a condenser cooling fan 123. The compressor 121 compresses a gaseous body at a low pressure returned from the refrigerant pipe 130 into a high-temperature high-pressure (for example, 70° C. to 80° C.) gaseous body. By increasing the pressure of the refrigerant, the compressor 121 enables the refrigerant to be easily changed into a liquid by the condenser 122, and creates a refrigerant flow. The condenser 122 changes the refrigerant into a high pressure liquid refrigerant (for example, 30° C. to 40° C.) by drawing heat from the high-temperature high-pressure gaseous refrigerant. The condenser cooling fan 123 cools the condenser 122 by blowing external air to the condenser 122.

The freezing machine 120 can cool a plurality of showcases 50 by connecting the refrigerant pipe 130 to the plurality of showcases 50.

The digital smart real showcase control system 100 composes a freezing cycle enabling refrigerating or freezing by circularly connecting the compressor 121, the solenoid valve 113, the expansion valve 114, the cooler 116, and the condenser 122. As the compressor 121, for example, a rotary type, scroll type, or reciprocating type compressor can be used.

Hereinafter, operation of the digital smart real showcase control system 100 configured as described above is described.

[Energy-Saving Control Operation Based on External Air Temperature Prediction]

First, an energy-saving control operation of the digital smart real showcase control system 100 is described.

FIG. 3 is a flowchart showing an energy-saving control operation of the digital smart real showcase control system 100.

First, in Step S1, the external air temperature input unit 11 inputs external air temperature information from the external air thermometer 20 installed outdoors.

In Step S2, the external air temperature input unit 11 stores the external air temperature information in the external air temperature table 12.

In Step S3, the external air temperature prediction unit 13 predicts a future external air temperature from a current external air temperature and past external air temperature changes, and passes the predicted external air temperature to the showcase control unit 18 and the air conditioning control unit 19.

When adopting the above-described <<past data-using prediction method>>, the external air temperature prediction unit 13 stores, for example, external air temperatures over the past one year in the external air temperature table 12 in advance, and predicts an external air temperature by reading out the stored external air temperature as an external air temperature predicted value. The prediction is performed with respect to the current external air temperature. The external air temperature prediction unit 13 predicts how the temperature will change (increase or decrease, and the degree of the increase or decrease) in the future (in how many minutes) on the basis of the current external air temperature. The external air temperature prediction unit 13 may predict an external air temperature by using the above-described <<external data-using prediction method>>.

In Step S4, the indoor temperature input unit 14 (refer to FIG. 1) inputs indoor temperature information from a measured value of the indoor thermometer 30.

In Step S5, the indoor humidity input unit 15 (refer to FIG. 1) inputs indoor humidity information from a measured value of the indoor hygrometer 40.

In Step S6, the indoor enthalpy prediction unit 17 calculates an enthalpy (a total wet air heating value of indoor air) from the inputted indoor temperature and indoor humidity, and stores the calculated enthalpy in the indoor enthalpy table 16.

In Step S7, the indoor enthalpy prediction unit 17 predicts a future indoor enthalpy from a current indoor enthalpy and past indoor enthalpy changes stored in the indoor enthalpy table 16.

In Step S8, the showcase control unit 18 controls the showcase 50 based on the predicted external air temperature and the predicted indoor enthalpy. The showcase control unit 18 controls the showcase 50 based on the predicted external air temperature and the predicted indoor enthalpy that are future predicted values, so that a quick and proper showcase control is realized. In the present embodiment, the showcase control unit 18 uses not only the predicted external air temperature but also the prediction control (refer to FIG. 5) according to a length of the refrigerant pipe 130 in combination, so that a quicker and more proper showcase control is realized.

In Step S8, the air conditioning control unit 19 controls the air conditioner 60 based on the predicted external air temperature and the predicted indoor enthalpy, and ends the processing of this flow. The air conditioning control unit 19 controls the air conditioner 60 based on the predicted external air temperature and the predicted indoor enthalpy that are future predicted values, so that a quick and proper air conditioning control is realized.

In this way, the digital smart real showcase control system 100 predicts an indoor enthalpy as well as an external air temperature, and controls the showcase 50 based on the predicted external air temperature and indoor enthalpy.

In the present embodiment, the showcase 50 is controlled based on an external air temperature not by following an external air temperature but based on an external air temperature predicted in advance, so that the showcase 50 is quickly and properly controlled, and accordingly, the showcase 50 can be controlled with minimum required energy.

Further, an indoor enthalpy is predicted as well as an external air temperature, and the showcase 50 is controlled based on the predicted external air temperature and indoor enthalpy, so that by reflecting an estimation result of a predicted heat load in showcase control, a highly effective energy-saving control is realized.

TABLE 1 Outdoor air Outdoor air temperature Enthalpy Operation Control Control Time temperature +bias coefficient Enthalpy coefficient coefficient coefficient minute  1:00 25.1 28.1 0.78 57.6 1.04 0.51 0.29 9  2:00 24.8 27.8 0.78 57.6 1.04 0.51 0.30 9  3:00 24.6 27.6 0.77 56.7 1.02 0.50 0.30 9  4:00 24.6 27.6 0.77 57.1 1.03 0.50 0.30 9  5:00 24.2 27.2 0.76 56.6 1.02 0.49 0.31 9  6:00 24.9 27.9 0.78 56.5 1.02 0.50 0.30 9  7:00 27.0 30.0 0.84 56.2 1.01 0.54 0.28 8  8:00 28.1 31.1 0.88 55.8 1.01 0.56 0.27 8 22:00 27.0 30.0 0.84 46.5 0.84 0.45 0.33 10 23:00 26.9 29.9 0.84 48.5 0.88 0.46 0.32 10 24:00 26.6 29.6 0.83 55.7 1.01 0.53 0.28 9 Avr. 25.8 28.8 0.81 55.0 0.99 0.50 0.30 9  9:00 29.4 32.4 0.92 59.8 1.08 0.63 0.22 7 10:00 31.0 34.0 0.97 59.5 1.07 0.66 0.21 6 11:00 31.5 34.5 0.98 57.4 1.04 0.64 0.21 6 12:00 32.9 35.9 1.03 56.8 1.02 0.66 0.20 6 13:00 33.5 36.5 1.05 54.8 0.99 0.65 0.21 6 14:00 33.9 36.9 1.06 50.9 0.92 0.61 0.23 7 15:00 32.9 35.9 1.03 50.1 0.90 0.59 0.25 7 16:00 33.2 36.2 1.04 50.9 0.92 0.60 0.24 7 17:00 32.3 35.3 1.01 47.0 0.85 0.54 0.28 8 18:00 30.4 33.4 0.95 48.2 0.87 0.52 0.29 9 19:00 29.2 32.2 0.91 46.4 0.84 0.48 0.31 9 20:00 28.1 31.1 0.88 45.6 0.82 0.46 0.33 10 21:00 27.4 30.4 0.86 43.3 0.78 0.42 0.35 10 Avr. 31.2 34.2 0.98 51.6 0.93 0.57 0.26 8 Ag. Av 28.5 31.5 0.89 53.3 0.96 0.54 0.28 8 Avr.: Average Ag. Av.: Aggregate average

Application Example

Next, an application example of an energy-saving control operation based on external air temperature prediction is described.

Table 1 shows an example of external air temperatures, enthalpies, coefficients, and control minutes to be stored in the external air temperature table 12 and the indoor enthalpy table 16 (storage means). Table 1 stores hourly external air temperatures (° C.), +biases (° C.), external air temperature coefficients, enthalpies (kJ/kg D.A.), enthalpy coefficients, operation coefficients, control coefficients, and control minutes (minutes). For example, the coefficients are according to the hourly external air temperatures and indoor air moisture heating value enthalpies (kJ/kG D.A.).

Table 1 is referred to at prediction time by the external air temperature prediction unit 13 and the indoor enthalpy prediction unit 17.

As the external air temperature (° C.) in Table 1, in the present embodiment, a predicted external air temperature is used (hereinafter, as an external air temperature, a predicted external air temperature is used).

The +bias (° C.) in Table 1 is external air temperature+condenser bias temperature (for example, in Table 1, 3.0). This +bias is a bias when considering that a temperature around the condenser is high.

The external air temperature coefficient in Table 1 is external air temperature/reference external air temperature (for example, in Table 1, 32.0).

The enthalpy (kJ/kg D.A.) in Table 1 is calculated from an indoor temperature and an indoor humidity (refer to Step S6 in FIG. 3).

The enthalpy coefficient in Table 1 is enthalpy/reference enthalpy (for example, in Table 1, 55.42).

The operation coefficient in Table 1 is external air temperature coefficient×enthalpy coefficient×reference operation coefficient (for example, in Table 1, 0.63).

The control coefficient in Table 1 is (1−operation coefficient)×safety factor (for example, in Table 1, 0.60).

The control minute (minutes) in Table 1 is control coefficient×reference control minute (for example, in Table 1, 30). The control minute is a numeral representing, by setting 30 minutes as a unit time, for how many minutes the operation of the freezing machine 120 is to be stopped, that is, the solenoid valve 113 is closed, in the unit time. For example, “9” means that operation is stopped for 9 minutes within 30 minutes for energy saving. During closing of the store, energy is greatly saved, and during opening of the store, small energy is saved.

The air conditioning control unit 19 shown in FIG. 1 performs an energy-saving control of the air conditioner 60 by an amount (control minute) corresponding to a control rate. For example, when the control rate is 0.40, operation of the air conditioner 60 is stopped by 40% in a predetermined pattern, or the air conditioner 60 is inverter-controlled with electric power as much as 60% of a rated power usage.

In this way, in the present embodiment, after the energy-saving control of the air conditioner 60 in a sales-space in which the showcase 50 is installed, the air conditioner 60 is further controlled so as to prevent excessive operation of the showcase control, and accordingly, a freezing or refrigerating burden on the showcase 50 is reduced, and this eventually greatly contributes to overall energy-saving of the store including the showcase 50.

[Showcase Control Operation of Showcase Control Unit 18]

<<Basic Control>>

The showcase control unit 18 is installed for, for example, each showcase 50, and performs a control for cooling to a target temperature suitable for products displayed on store shelves. The showcase control unit 18 may collectively control a plurality of showcases 50.

The showcase control unit 18 consists of a CPU (Central Processing Unit) or the like, and the CPU is made to function as a digital smart real showcase control system by executing a showcase control program.

By detecting a temperature of the showcase 50 and controlling opening and closing of the solenoid valve 113 of the freezing machine 120 so that the detected temperature becomes close to a target temperature, the showcase control unit 18 performs a control to maintain the temperature of the showcase 50 at a temperature within a certain range (a target temperature between a lower limit temperature and an upper limit temperature) suitable for preservation of products (for example, frozen food). A cooling temperature inside the showcase 50 differs depending on the kind of stored product, and is set for each showcase 50. For example, the cooling temperature is set to 7° C. for fruits and vegetables, 5° C. for daily foods (generic term of foods that need to be refrigerated and have short expiration dates), 0° C. for fresh fish and dressed meat, −18° C. for frozen food, and −26° C. for ice cream.

Further, the showcase control unit 18 controls the operation of the showcase 50 by a temperature-dependent control coefficient being a control coefficient corresponding to deviation of the temperature of the showcase 50 from the target temperature. Specifically, for example, when products are fruits and vegetables, the target temperature is set to 7° C., a permissible temperature range is ±4° C., and the control coefficient is 0.35, by defining a deviating temperature coefficient as (showcase temperature (° C.)−target temperature (7° C.)/permissible temperature range (4° C.), the showcase 50 is controlled for energy saving by temperature-dependent control coefficient=control coefficient (0.35)−(control coefficient (0.35)×deviating temperature coefficient). For example,

when the temperature of the showcase 50 is 3° C., the deviating temperature coefficient is −1=(3−7)/4, and the temperature-dependent control coefficient is 0.70=0.35+(0.35×1),

when the temperature of the showcase 50 is 4° C., the deviating temperature coefficient is −0.75=(4−7)/4, and the temperature-dependent control coefficient is 0.61=0.35+(0.35×0.75),

when the temperature of the showcase 50 is 5° C., the deviating temperature coefficient is −0.5=(5−7)/4, and the temperature-dependent control coefficient is 0.53=0.35+(0.35×0.5),

when the temperature of the showcase 50 is 6° C., the deviating temperature coefficient is −0.25=(6−7)/4, and the temperature-dependent control coefficient is 0.44=0.35+(0.35×0.25),

when the temperature of the showcase 50 is 7° C., the deviating temperature coefficient is 0=(7−7)/4, and the temperature-dependent control coefficient is 0.35=0.35−(0.35×0),

when the temperature of the showcase 50 is 8° C., the deviating temperature coefficient is 0.25=(8−7)/4, and the temperature-dependent control coefficient is 0.26=0.35−(0.35×0.25),

when the temperature of the showcase 50 is 9° C., the deviating temperature coefficient is 0.5=(9−7)/4, and the temperature-dependent control coefficient is 0.18=0.35−(0.35×0.5),

when the temperature of the showcase 50 is 10° C., the deviating temperature coefficient is 0.75=(10−7)/4, and the temperature-dependent control coefficient is 0.09=0.35−(0.35×0.75), and

when the temperature of the showcase 50 is 11° C., the deviating temperature coefficient is 1=(11−7)/4, and the temperature-dependent control coefficient is 0=0.35−(0.35×1).

<<Prediction Control According to Length of Refrigerant Pipe 130>>

Next, a prediction control operation according to a length of the refrigerant pipe 130 is described.

The showcase control unit 18 controls the showcase 50 based on a predicted external air temperature for a time, corresponding to a length of the refrigerant pipe 130, ahead (future). Specifically, the control is as follows.

The refrigerant pipe 130 shown in FIG. 2, connecting the showcase 50 and the condenser 122, has a length of several to several tens of meters. Therefore, a control result by the showcase control unit 18 is not immediately reflected in the showcase 50, and a delay from a predicted external air temperature, corresponding to the length of the refrigerant pipe 30, occurs. Here, the length of the refrigerant pipe 130 is already known for each showcase 50.

The showcase control unit 18 performs a prediction control to eliminate the delay from the predicted external air temperature, corresponding to the length of the refrigerant pipe 130. Specifically, the showcase control unit 18 controls the showcase 50 based on a predicted external air temperature for a time, corresponding to the length of the refrigerant pipe 130, ahead (future). That is, the showcase control unit 18 determines prediction time intervals (how many minutes later the prediction is for). As a result, the control timing differs depending on the length of the refrigerant pipe 130.

Here, there is also a case where a plurality of showcases 50 are controlled by one condenser 122. In this case, the showcase control unit 18 controls the showcase 50 based on a predicted external air temperature for a time, corresponding to an average length of the refrigerant pipes 130 for the plurality of showcases 50, ahead.

<<Bias External Air Temperature Control by Adding Prediction Bias External Air Temperature to Predicted External Air Temperature>>

The showcase control unit 18 performs a bias external air temperature control by adding a prediction bias external air temperature to a predicted external air temperature. A temperature around the compressor 121 shown in FIG. 2 is high, and is normally higher than an external air temperature that a meteorological agency issued. The showcase control unit 18 controls the showcase 50 around the compressor 121 based on a predicted external air temperature obtained by adding a prediction bias external air temperature to a predicted external air temperature.

In this way, the showcase control unit 18 predicts an external air temperature for a time (for example, 5 minutes or 3 minutes, etc.), corresponding to a length of the refrigerant pipe 130, ahead (future), adds a prediction bias temperature to the predicted external air temperature, and stops the operation of the freezing machine 120 for a control minute (unit: minutes) corresponding to the predicted external air temperature to which the prediction bias temperature is added. The showcase control unit 18 repeats temperature addition and operation stoppage of the freezing machine 120 according to the “prediction control according to length of refrigerant pipe 130” and the “bias external air temperature control.”

As described above, the digital smart real showcase control system 100 comprises the external air temperature table 12 that stores past external air temperatures for prediction of an external air temperature, the external air temperature prediction unit 13 that predicts a future predicted external air temperature from inputted external air temperature information based on the external air temperature table 12, and the showcase control unit 18 that controls the showcase temperature based on the predicted external air temperature.

In a conventional example, an external air temperature was detected and fed-back, so that a follow-up control was performed, and a quick and proper control could not be performed. On the other hand, in the present embodiment, the showcase is controlled not by following an external air temperature but based on an external air temperature predicted in advance, so that the showcase is quickly and properly controlled, and accordingly, the showcase can be controlled with minimum required energy.

In addition, the showcase control unit 18 predicts a predicted external air temperature for a time, corresponding to the length of the refrigerant pipe 130, ahead, from inputted external air temperature information, and controls the temperature of the showcase 50 based on the predicted external air temperature.

Accordingly, the showcase can be controlled based on a predicted external air temperature for a time, corresponding to the length of the refrigerant pipe, ahead (future), so that the showcase is quickly and properly controlled, and accordingly, the showcase can be controlled with minimum required energy.

In addition, the digital smart real showcase control system 100 comprises the indoor enthalpy prediction unit 17 that calculates an enthalpy being a total wet air heating value of indoor air based on inputted temperature and humidity of indoor air, and predicts a future indoor enthalpy based on the calculated indoor air enthalpy and past indoor enthalpies stored in the indoor enthalpy table 16, and the showcase control unit 18 that controls the showcase temperature based on the predicted indoor enthalpy.

Accordingly, an indoor enthalpy is predicted, and based on the predicted external air temperature and indoor enthalpy, the showcase is controlled, so that by reflecting an estimation result of a predicted heat load in showcase control, a highly effective energy-saving control is realized.

For this indoor enthalpy prediction, a predicted external air temperature may be considered. An indoor temperature is influenced by an external air temperature through a building. That is, as the external air temperature changes, after the elapse of a predetermined time, the indoor temperature changes under the influence of the external air temperature change. Therefore, by adding a predicted external air temperature as a factor for prediction of an indoor enthalpy, a more accurate prediction is realized.

The description given above is the illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this, but includes other modifications and application examples without departing from the spirit of the present invention described in the claims.

In the present embodiment, both of the external air temperature prediction by the external air temperature prediction unit 13 and the showcase control based on a predicted external air temperature according to a length of the refrigerant pipe 130 by the showcase control unit 18 are used, however, either one may be used. Likewise, the bias external air temperature control by the showcase control unit 18 may also be used alone, or may be combined with both or either one of the above-described external air temperature prediction and showcase control.

The above-described embodiment examples describe the present invention in detail in an understandable way, and the present invention is not necessarily limited to one comprising all configurations described above. Part of a configuration of an embodiment example can be replaced by a configuration of another embodiment example, and to a configuration of an embodiment example, a configuration of another embodiment example can be added. Part of a configuration of each embodiment example can be subjected to addition of other configurations, deletion, and replacement.

The present embodiment is an example of application to an air conditioning control system, and an air conditioning control is not essential for the present invention. In the present embodiment, for convenience of description, the respective control means, that is, the air conditioning control unit 19 (control means) and the showcase control unit 18 (control means) are described separately, however, the controls may be performed by one control unit. Likewise, each table may be stored in any medium as a storage unit.

The showcase may be a case having a freezer-refrigerator function. The showcase includes a refrigerator and a freezer. That is, the showcase is used for convenience of description, and may be a storage for frozen and refrigerated products that do not necessarily have to be shown to people, and also with this, the same effect can be obtained.

In the above-described embodiment, the names specified as a digital smart real showcase control system and a digital smart real showcase control method are used, however, these are used for convenience of description, and the name of the system may be a showcase control device, and the name of the method may be a showcase control and management method, etc.

The present digital smart real showcase control processing described above is also realized by a program for functioning this main digital smart real showcase control processing. This program is stored in a computer-readable storage medium. The storage medium in which this program is recorded may be a ROM itself of the present digital smart real showcase control system, or a CD-ROM or the like that can be read by being inserted in a program reading device such as a CD-ROM drive provided as an external storage device.

The storage medium may be a magnetic tape, a cassette tape, a flexible disk, a hard disk, and an MO/MD/DVD, etc., or a semiconductor memory.

REFERENCE SIGNS LIST

-   11 External air temperature input unit (external air temperature     input means) -   12 External air temperature table (storage means) -   13 External air temperature prediction unit (external air     temperature prediction means) -   14 Indoor temperature input unit (indoor temperature input means) -   15 Indoor humidity input unit (indoor humidity input means) -   16 Indoor enthalpy table (storage means) -   17 Indoor enthalpy prediction unit (indoor enthalpy prediction     means) -   18 Showcase control unit (control means) -   19 Air conditioning control unit (control means) -   20 External air thermometer -   30 Indoor thermometer -   40 Indoor hygrometer -   50 Showcase -   50 a Showcase main body -   60 Air conditioner -   100 Digital smart real showcase control system -   110 b Machine room -   111 Air outlet -   112 Suction opening -   113 Solenoid valve -   114 Expansion valve -   115 Fan motor -   116 Cooler -   117 Shelf plate (store shelf) -   118 Bottom plate (store shelf) -   119 Air curtain -   120 Freezing machine -   121 Compressor -   122 Condenser -   123 Condenser cooling fan -   130 Refrigerant pipe -   131 Temperature sensor 

1. A digital smart real showcase control system comprising: an indoor temperature input means configured to input indoor temperature information; an indoor humidity input means configured to input indoor humidity information; an enthalpy calculation means configured to calculate an enthalpy being a total wet air heating value of indoor air from an indoor temperature inputted from the indoor temperature input means and an indoor humidity inputted from the indoor humidity input means; an external air temperature input means configured to input external air temperature information; an external air temperature prediction means configured to predict a future predicted external air temperature from external air temperature information inputted by the external air temperature input means; and a control means configured to control a showcase temperature based on a predicted external air temperature predicted by the external air temperature prediction means, wherein the control means performs energy-saving control of the showcase temperature by a quantity of a temperature-dependent control coefficient, wherein temperature-dependent control coefficient=control coefficient−(control coefficient×deviating temperature coefficient) control coefficient=(1−operation coefficient)×safety factor deviating temperature coefficient=(showcase temperature−target temperature)/permissible temperature range operation coefficient=external air temperature coefficient×enthalpy coefficient×reference operation coefficient external air temperature coefficient=predicted external air temperature/reference external air temperature enthalpy coefficient=enthalpy/reference enthalpy.
 2. The digital smart real showcase control system according to claim 1, comprising: a storage means configured to store past external air temperatures, wherein the external air temperature prediction means predicts a predicted external air temperature based on data stored in the storage means.
 3. (canceled)
 4. The digital smart real showcase control system according to claim 1, wherein the external air temperature prediction means predicts a future predicted external air temperature for a time, corresponding to a length of a refrigerant pipe connecting the showcase and a freezing machine, ahead.
 5. The digital smart real showcase control system according to claim 1, comprising: an indoor enthalpy prediction means configured to predict a predicted indoor enthalpy from the indoor temperature inputted from the indoor temperature input means and the indoor humidity inputted from the indoor humidity input means, wherein the control means controls a showcase temperature based on an indoor enthalpy predicted by the indoor enthalpy prediction means.
 6. The digital smart real showcase control system according to claim 1, wherein the control means controls the showcase based on a predicted bias external air temperature obtained by adding a bias temperature for correcting a high temperature around a condenser to the predicted external air temperature.
 7. A digital smart real showcase control method comprising: an indoor temperature input step of inputting indoor temperature information; an indoor humidity input step of inputting indoor humidity information; an enthalpy calculation step of calculating an enthalpy being a total wet air heating value of indoor air from an indoor temperature inputted from the indoor temperature input means and an indoor humidity inputted from the indoor humidity input means; an external air temperature input step of inputting external air temperature information; an external air temperature prediction step of predicting a future predicted external air temperature from external air temperature information inputted by the external air temperature input step; and a control step of controlling a showcase temperature based on a predicted external air temperature predicted by the external air temperature prediction step, wherein the control step performs energy-saving control of the showcase temperature by a quantity of a temperature-dependent control coefficient, wherein temperature-dependent control coefficient=control coefficient−(control coefficient×deviating temperature coefficient) control coefficient=(1−operation coefficient)×safety factor deviating temperature coefficient=(showcase temperature−target temperature)/permissible temperature range operation coefficient=external air temperature coefficient×enthalpy coefficient×reference operation coefficient external air temperature coefficient=predicted external air temperature/reference external air temperature enthalpy coefficient=enthalpy/reference enthalpy.
 8. (canceled)
 9. A tangible non-transitory computer-readable storage medium, the computer-readable storage medium is configured to store a program executable by a digital smart real showcase control system, the digital smart real showcase control system upon execution of the program is configured to perform the digital smart real showcase control method of claim
 7. 